Condition responsive device



March 2 1934- H. J. SMITH CONDITION RESPONSIVE DEVICE Filed Sept. 1, 1932 3 Sheets-Sheet 1 INVE OR flf// ATTORNEY March 27, 1934. H. J. SM ITH CONDITION RESPONS-IVE DEVICE Filed Sept. 1, 1952 3 Shets-Sheet 2 INVEN R ATTORNEY March 27, 1934. H. J. SMITH CONDITION RESPONSIVE DEVICE 3 Sheets-Sheet 3 Filed Sept. 1, 1952 Patented Mar. 27, 1934 PATENT OFFICE CONDITION RESPONSIVE DEVICE Hazor J. Smith,

Springfield, Mass.

Application September 1, 1932, Serial No. 631,339

34 Claims.

This invention relates to a condition-responsive apparatus and more particularly to a temperature or pressure-operated control for an electric circuit.

This application is a continuation-in-part of my copending application, Serial No. 515,787, filed February 14, 1931, for Condition control apparatus.

An object of the invention is to provide a re- -versible, modulated control, operable in response to variations in temperature or pressure.

Another object is to provide a reversible, stepby-step control for an electric circuit.

Another object is to provide a simple, convenient and dependable device of the type above indicated.

The invention also consists in certain new and original features of construction and combinations of parts hereinafter set forth and claimed.

Although the novel features which are believed to be characteristic of this invention will be particularly pointed out in the claims appended thereto, the invention itself, as to its objects and advantages and the manner in which it may be carried out, may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part thereof, in the various figures of which like reference characters have been used to designate like parts.

In the drawings, Figure 1 is a side elevation of one form of control unit constructed in accordance with the present invention;

Figure 2 is a plan view of the control unit of Figure 1 with the cover removed;

Figure 3 is a section taken on the line 3-3 of Figure 2;

Figure 4 is a plan view of a modified form of control unit embodying the present invention;

Figure 5 is a side elevation of the control unit of Figure 4 with the cover partly broken away;

Figure 6 is a plan view of the control unit of Figure 4 with the index arm and operating mechanism removed;

Figure 7 is a section taken on line 77 of Figure 6; and

depending peripheral flange 2 and a cover 3. Mounted on the base 1 and preferably integrally therewith are flanges 4 and 5. Also mounted on the base is a bracket 6. A lever 7 is pivotally supported in the bracket 6 by means of the adjustable pivot pins 8 and 9-. The lever 7 has depressions 10 and 11 on either side thereof. The base of the heat-responsive or pressure-responsive element 12 is mounted on the flange 4. This element may consist of a bellows charged with an expansible fluid. As the details of construction of such bellows are well known, no further description thereof is necessary. The bellows 12 is provided at its free end with a conical pin 13 adapted to seat in the depression 10 on the lever 77. A threaded bushing 16 is mounted in the flange 5. A pin 14 is mounted slidably in the bushing 16. The pin 14 is provided with a conical end adapted to engage the depression 11 on the lever '7. The pin 14 is provided with a washer 15. A spring 17 is held between the washer 15 and the bushing 16 and tends to urge the pin 14 forward into engagement with the lever '7. The spring 17 tends to counterbalance or oppose the action of the bellows 12. The bushing 16 is provided with an indicator handle 16'. The casing 3 is provided with. a dial marked off to indicate, for example, degrees of temperature. The rotation of the handle 16 advances or retracts the bushing 16 and increases or decreases the compression of the spring 1'7, thereby varying the operative effect of the bellows 12.

Pivoted on the lower end of the lever '7 at 18 is a second lever 19, preferably made from insulating material. The lever 19 is provided with metal contact members 21 and 22. Mounted on the base 1 by means of the binding posts 23 and 24 are the adjustable contacts 25 and 26. The adjustment of these contacts is efiected by means of the nuts 27 and 28. The contact 25 is adapted to contact with the contact 21 on the lever 19, and the contact 26 is adapted to contact with the contact 22 on the lever 19. The concontact member 22. The binding posts 23 and 24 are connected to a control mechanism (not shown) by means of a conduit 33. Mounted on the lower end of the base 1 are two series of contact members 35 and 36. The contact members 35 are adapted to be engaged by the brush 29, whereas the contact members 36 are adapted to be engaged by the brush 30. The brush 29 with the series of contacts 35 and the brush 30 with the series of contacts 36 constitute progressive connecting switches which may be used, for example, to control the extent of movement of the motor-control unit above mentioned. The reversing switches comprising the contacts 21, 25 and 22, 26 are operated by the condition-responsive means in advance of and independently of the actuation of the progressive connecting switches in a manner to be pointed out. Each element of the contact members 35 and 36 is adapted to be connected by suitable wires to-the motor mechanism (not shown).

The control apparatus, illustrated in Figure 2, is shown at rest at a predetermined temperature or pressure, for instance, at a temperature of 70. Upon a drop in temperature, the gas pressure in the bellows 12 falls, permitting the bellows 12 to be compressed by the action ofthe spring 17 on the pin 14, pressing against the lever 7 and on the pin 13 of the bellows. This will cause the lever 7 carrying the lever 19 to move to the left. This movement of the lever 7 to the left will cause the lever 19 to pivot about brushes 29 and 30 and will cause contact 21 to engage contact 25. A very slight movement of the lever 7 is necessary to effectuate this, since the lower portion of the lever 19 is frictionally held against movement by the brushes 29 and 30 resting on some one of the contact points 35 and 36. Thus,

in Figure 2, the brushes 29 and 30 are shown resting on X and Y Should the temperature continue to drop, the bellows 12 will be still further compressed by the action of the spring 17, and the lever 7 will swing still further to the left. Since the upper part of the lever 19 is in contact with the contact member at 25, it can move no further to the left. This causes the lever 19 to pivot about said contact 25, thereby causing the brushes 29 and 30 to move to the left so that the brush 29 will then engage the contact member X of the contact member 35. It will also cause the brush 30 to move over to the contact member Y Further contraction of the bellows 12 will permit the spring 17 to push the lever 7 still further to the left, causing the brushes 29 and 30 to ride over and engage the contact members X and Y respectively of the contact members 35 and 36.

An increased temperature or pressure will cause the bellows 12 to expand, thereby compressing the spring 17 and causing the lever 7 to move to the right. Since the lower end of the lever 19 is held against free movement by frictional engagement of the brushes 29 and 30 on the contact members 35 and 36, the upper part of the lever 19 will move to the right, completing the circuit through the contact points 22 and 26. Thereafter, further expansion of the bellows 12 will cause the brush 30 to contact progressively with the contact members Y Y Y Y and Y It will be noted that at the predetermined temperature or pressure, say a temperature of 70,

sume a median position between the contacts 25 and 26. In the normal operation of this or carried by the base 40.

device, the contacts will remain as shown in Figure 2, the only change being that as the temperature or pressure rises or falls slightly, contact will be made at 26 or 25. Brushes 29 and 30 are only swung to the extreme point when there is an abnormal or decided change in condition. Thus, it will be seen that the device is adapted to control the fuel supply and/or drafts of a furnace and will operate to slowly open or close the drafts and/or fuel supply as the desired temperature is approached, and then to hold the drafts and fuel supply at the point necessary to maintain the predetermined temperature.

In operating the device directly in response to pressure variations, the bellows can be connected to the pressure line or, for example, can be directly connected to a steam boiler. The spring '17 would be adjusted to balance the pressure in the bellows 12 at the predetermined point. The operation will then be, as has been described, to increase or decrease the fuel supply the amount necessary to compensate for a drop or increase in pressure.

Referring to the control unit illustrated in Figures 4 to 8, the unit is shown as comprising a base 40 having a downwardly extending flange 41, which is adapted to rest on a supporting surface. The base 40 also carries a stud 42 to which an arm 44 is pivoted, as by a pin 43, which is threaded into said stud. The arm 44 has secured thereto at its free end an insulating member 45 carrying a pair of contacts 46 and 47, which are mounted respectively on contact strips 48 and 49 provided with connecting ears 50 and 51 respectively. The ears 50 and 51 are connected to binding posts 52 and 53 respectively by flexible connectors 54 and 55. The binding posts 52 and 53 carry adjustable stops 56 and 57 respectively which limit the movement of the contact lever to be described.

A temperature or pressure-responsive bellows 60 of any well-known type is provided with a base 61 which is anchored in a bushing 62, threaded or otherwise secured in a bracket 63 formed on or attached to the base 40. The free end of the bellows 60 is provided with a pin 65, which seats in a recess 66 in the arm 44.

For resiliently holding the arm 44 in engagement with a pin 65, a second bellows 70 is provided having a base 71 carried in a bushing 72, which is threaded into a bracket 73 formed on The bushing 72 is provided with a pair of recesses 74 adapted to receive projecting arms 75 of an adjusting handle 76. The free end of the bellows 70 is provided with a pin 77 which seats in a recess 78 formed in the arm 44. -By means of the handle 76, the bushing 72 is moved longitudinally in the bracket 73, thereby causing longitudinal movement of the base 71 of the bellows 70 and varying force applied thereby to the arm 44. This in turn varies the compression of the bellows 60 and controls the operating range of the device.

A contact lever 80 (Figure 8) is mounted on the base 40 by a pivot pin 81, which may be secured therein in any convenient manner, as by nuts 82. The lever 80 is preferably mounted beneath the lever 44, which is elevated sufliciently to provide clearance therefor. The lever 80 carries at one end a pair of contacts and 86 which are adapted to engage respectively contacts 46 and 47 carried by the lever 44. Contacts 46, 85 and 47, 86 are adapted to constitute reversing contacts of, for example, a reversing 150 85 or 47, 86. Further movement of the arm-.44" will cause pivotal movement of the arm 80 about connected byconducting strips 87 and 88 to a pair of brushes 89 and 90, which are adapted to contact with sets of contacts 91 and 92 respectively, said sets of contacts and brushes comprising a progressive switch means.

The relationship between the contacts 46 and 47 and contacts 85 and 86 is such that the lever 44 may ride free in a middle position with both contacts broken. One or the other of the contacts is completed, however, in response to movement of the lever 44 in either direction with respect to the lever 80.

For indicating the adjusted position of the bellows '70 with respect to the bracket '73 and consequently indicating the range of operation of the device, there is provided an index arm 95 (Figures 4 and 5) carrying a suitably graduated scale 96 which is viewed, for example, through an aperture 97 in a cover 98. The index arm 95 is pivoted to a plate 100 carried upon supporting pins 101 which are mounted on the base 40. A lever 102 is pivoted to the plate 100 as by a pivot pin 103 and is provided with a downwardly extending lug 104, which is pivoted to said lever by a pin 105. The lug 104 carries a rod 106 which is rotatably held therein, as by a collar 107, and is threaded into flanges 108 formed on a depending portion 109 of a link 110.

The link 110 is pivoted to the index arm 95, as by a pivot 111, and is provided with an arm 112 carrying a spring 113, which is anchored to a stationary ear, 114 on the plate 100. The lever 102 is provided at its free end with a depending flange 115 which is adapted to bear against the end of thesylphon bellows 70, whereby the pivotal position of the lever 102 is determined by the longitudinal position of said bellows.

In the operation of the form of the invention above described, it is to be understood that the be controlled by the unit. The resilience of the bellows may be varied by applying a compressible fluid, such as compressed air, thereto. The pressure exerted by said bellows 70 upon the arm 44 may accordingly be varied by variation in the pressure of the medium within said bellows and by adjustment of the longitudinal position of the bellows in the bracket '73.

Assuming the device to be in the position shown, any change in the temperature or pressure supplied to the bellows 60 will cause pivotal movement of the arm 44 about the pin 43, thereby closing one of the pairs of reversing contacts 46,

the pin 81 and thereby cause the brushes 89 and 90 to move over the progressive contacts 91 and 92.

It is to be understood that the reversing contacts 46, 85, 4'7, 86 and the progressive contacts 91 and 92 may be connected to a suitable reversible motor-control unit of any desired type and are adapted to cause reversible step-by-step operation thereof.

The position of the bellows 70 controls the position of the lever 102, and through the linkage above described, controls the position of the index 96, which may be calibrated to indicate the operating range of the device.

While certain preferred forms of the invention have been disclosed for the purpose of illustration,

it is obvious that the invention is not to be limited thereto but only accordance with the scope of the following claims when construed in view of the prior art.

I claim:

1. A device of the character described comprising condition-responsive means, a first switch means, a first means operating said switch means in response to slight reversals in movement of said condition-responsive means at any given position, a second switch means independent of said first means and means operating said second switch means in response to continued movement of said condition-responsive means in either direction.

2. A device of the character described comprising condition-responsive means, a first switch means, a first means operating said switch means in response to slight reversals in movement of said condition-responsive means at any given position, progressive switch means independent of said first means and means for operating said progressive switch means in response to continued movement of said condition-responsive means in either direction.

3. In combination, a progressive switch means, a double-throw switch means, condition-responsive means, and means whereby reversal in movement of said condition-responsive means at any given position first reverses said double-throw switch means and subsequently causes operation of said progressive switch means.

4. In combination, a double-throw switch means, a progressive switch means, means operating said double-throw switch means regardless of the position of said progressive switch means, means for operating said progressive switch means in a given direction without influencing the position of said double-throw switch means, and means whereby reversal of said double-throw switch means occurs prior to reversal in operation of said progressive switch means.

5. In combination, a pivoted lever, means actuating said lever, a double-throw switch, means actuating said double-throw switch in response to reversals in movement of said lever at any given position, a progressive switch independent of said double-throw'switch and means actuating said progressive switch in response to continued movement of said lever in either direction.

6. In combination, a pivoted lever, means actuating said lever, progressive switch means, brushes cooperating therewith and actuated by movement of said lever in a given direction, doublethrow switch contacts, and means actuated by reversal of movement of said lever at any given position for actuating-said double-throw switch contacts.

7. A switchmechanism comprising a pivoted lever, means adapted to actuate said lever, a second pivoted lever, a double-throw switch actuated by said second lever, a progressive switch actuated by said second lever, and means ineluding said double-throw switch for controlling said second lever in accordance with the position of said first lever.

8. A switch mechanism comprising a pivoted lever, means adapted to actuate said lever, a second pivotedieve rfa double-throw switch actuated by said second lever, progressive contact means, brushes carried by said second lever and contacting with said progressive contact means, and means including said double-throw switch for controlling said second lever in accordance with the position of one of said first levers.

9. A switch mechanism comprising a pivoted lever, means adapted to actuate said lever, a second lever, double-throw switch contacts carried by said second lever, progressive switch means, and means actuating said progressive switch means by said second lever, said double-throw contacts and said first lever cooperating to actuate said second lever.

10. A switch mechanism comprising a pivoted lever, means adapted to actuate said lever, a second lever, double-throw switch contacts carried by said second lever, progressive switch means, and means actuating said progressive switch means by said second lever, said first lever engaging said double-throw contacts to actuate the same and after actuation thereof to cause pivotal movement of said second lever to thereby actuate said progressive switch means.

11. A switch mechanism comprising a pivoted lever, means adapted to actuate said lever, a second lever pivoted to said first lever, double-throw switch contacts carried by said second lever, progressive switch means, and means actuating said progressive switch means by said second lever, movement of said first lever first causing actuation of said double-throw contacts and then causing said second lever to pivot about said double-throw contacts and to actuate said progressive switch means.

12. In combination, a pivoted lever, conditionresponsive means actuating said lever, a double throw switch, means actuating said double-throw switch in responsive to reversals in movement of said lever, a progressive switch, and means independent of said double-throw switch actuating said progressive switch in response to continued movement of said lever in either direction.

13. In combination, a pivoted lever, conditionresponsive means actuating said lever, progressive switch means, brushes cooperating therewith and actuated by movement of said lever in a given direction, double-throw switch contacts, and

, means actuated by reversal of movement of said lever at any given position for actuating said double-throw switch contacts.

14. A switch mechanism comprising a pivoted lever, condition-responsive means adapted to ac-. tuate said lever, a second pivoted lever, a double-throw switch actuated by said second lever, progressive contact means, brushes carried by said second lever and contacting with said progressive contact means, and means including said double-throw switch for controlling said second lever in accordance with the position of said first lever.

15. A switch mechanism comprising a pivoted lever, condition-responsive means adapted to actuate said lever, a second lever, double-throw switch contacts carried by said second lever, pro-.

gressive switch means, and means actuating said progressive switch means by said second lever, said first lever engaging said double-throw contacts to'actuate the same and after actuation thereof to cause pivotal movement of said second lever to thereby actuate said progressive switch means.

16. A switch mechanism comprising a pivoted lever, condition-responsive means operatively connected to said lever, a double-throw switch actuated by said lever, and two sets of progressive switches independently actuated by said lever, said sets being respectively connected to the poles of said double-throw switch.

17. A switch mechanism comprising a pivoted lever, condition-responsive means operatively connected to said lever, a double-throw switch actuated by said lever, and two sets of progressive switches independently actuated by said lever, said sets being respectively connected to the poles of said double-throw switch, the construction being such that when the conditionresponsive means moves said lever in one direction, one contact of the double-throw switch is closed to complete the circuit through one of said sets of progressive switches and the other con tact of said double-throw switch is opened to disconnect the circuit through the other of said sets of progressive switches.

18. A switch mechanism comprising a doublethrow switch, two sets of progressive switches, a member carrying two contacts, each of which is adapted to successively make connection with the contacts of one of said sets of progressive switches, and condition-responsive means operatively connected to said member, the construction being such that when said condition-responsive means successively moves the member but slightly in opposite directions, the contacts of said double-throw switch are alternately opened and closed without changing the position of said progressive switches, and when the member is given a considerable movement in either direction, first a contact of said double-throw switch is closed and then each contact on said member successively makes connection with the contacts of the corresponding progressive switch.

19. A switch mechanism comprising a lever, condition-responsive means operatively connected to said lever, twa sets of contact members carried by said lever, a pair of stationary contact members adapted to contact respectively with the contacts of one of said sets, and a series of stationary contact members adapted to contact with the contacts of the other of said sets.

20. A switch mechanism comprising a pivoted lever, condition-responsive means operatively connected tosaid lever, a second lever operatively connected to said first lever, a pair of sets of contact members carried by said second lever, a pair of stationary contacts cooperating with the contacts of one of said sets, and a series of stationary contacts adapted to progressively cooperate with the contacts of the other of said sets.

21. A switch mechanism comprising a lever, condition-responsive means operatively connected, thereto, a second lever actuated by said first lever, a set of contact members carried by said second lever, a second set of contact members carried on said second lever, a pair of stationary contact members adapted to contact with the contact members of said first set, and a series of stationary contact members adapted to pro gressively contact with the contactmembers of said second set.

22. A switch mechanism comprising a lever, a condition-responsive bellows operatively connected to said lever, yieldable means opposing the action of said bellows, a second lever actuated by said first lever, and a pair of switch means independently actuated by said second lever.

23. A switch mechanism comprising a lever, a condition-responsive bellows operatively connected to said lever, yieldable means opposing the action of said bellows, a second lever actuated by said first lever, a double-throw switch, a. a progressive switch, and means independently operating said switches in accordance with the position of said second lever.

24. A switch mechanism comprising a lever, a condition-responsive bellows operatively connected to said lever, yieldable means opposing the action of said bellows, a second lever, doublethrow switch contacts carried by said second lever, progressive switch means carried by said second lever, and double-throw switch contacts carried by said first lever and adapted to engage the contacts carried by second lever to selectively close said contacts and to mechanically actuate said second lever so as to cause said second lever to actuate said progressive switch means.

25. A switch mechanism comprising a lever, a condition-responsive bellows operatively connected to said lever, a second bellows engaging said lever and opposing the action of said first bellows, a second lever, double-throw switch contacts carried by said second lever, progressive switch means carried by said second lever, and double-throw switch contacts carried by said first lever and adapted to engage the contacts carried by second lever to selectively close said contacts and to mechanically actuate said second lever so as to cause said second lever to actuate said progressive switch means.

26. A condition-responsive device comprising a pivoted lever, contact means opera-tively associated therewith, a condition-responsive bellows engaging said lever to cause pivotal movement thereof, a second bellows engaging said lever to oppose the action of said first bellows, and means to adjust the compression of one of said bellows to thereby adjust the range of operation of the device.

27. A condition-responsive device comprising a pivoted lever, contact means operatively associated therewith, a condition-responsive bellows engaging said lever to cause pivotal movement thereof, a second bellows engaging said lever to oppose the action of said first bellows, and means for longitudinally adjusting one of said bellows with respect to said lever to thereby vary the compression thereof.

28. A conditon-responsive device comprising a pivoted lever, contact means operatively associated therewith, a condition-responsive bellows engaging said lever to cause pivotal movement thereof, a second bellows engaging said lever to oppose the action of said first bellows, means for longitud'nally adjusting one of said bellows with respect to said lever to .thereby vary the compression thereof, and means actuated by longitudinal movement of said bellows to indicate the extent of such movement.

29. A condition-responsive device comprising a pivoted lever, contact means operatively assocated therewith, a pair of expansible bellows, means rigidly supporting one end of each of said bellows, the free ends thereof engaging said lever in opposed relationship, and means for longitudinally adjusting one of said supporting means with respect to said lever to thereby vary the compresson of said bellows.

30. A condition-responsive device comprising a pivoted lever, contact means operatively associated therewith, a pair of expansible bellows,

means rigidly supporting one end of each of said bellows, the free ends thereof engaging said lever in opposed relationship, means for longitudinally adjusting one of said supporting means with respect to said lever to thereby vary the compression of said bellows, a second pivoted lever engaging the adjustable part of said bellows and actuated in accordance with the longitudinal position thereof, and an index arm operatively associated with said second lever.

31. .A condition-responsive device comprising a pivoted lever, contact means operatively associated therewith, a pair of expansible bellows, means rigidly supporting one end of each of said bellows. the free ends thereof engaging said lever in opposed relationship, means for longitudinally adjusting one of said supporting means with respect to said lever to thereby vary the compression of said bellows, a second pivoted lever engaging the adjustable part of said bellows and actuated in accordance with the longitudinal position thereof, an index arm operatively associated with said second lever, and a cover for said device, said cover having an aperture registering with a part of said index arm to facilitate reading thereof.

32. In a condition-responsive device, a base, a lever pivoted thereon, a condition-responsive bellows mounted on said base and engaging said lever, a second lever pivoted to said base, progressive contacts carried by said base, brushes carried by said second lever and engaging said contacts, and pairs of contacts carried respectively by said first and second levers, said pairs of contacts being adapted to selectively close in response to movement of said first lever and, when closed, to cause pivotal movement of said second lever in response to continued movement of said first lever to thereby move said brushes over said progressive contacts.

33. In a condition-responsive device, a base, a lever pivoted thereon, a condition-responsive bellows mounted on said base and engaging said lever, a second lever pivoted to said first lever, progressive contacts carried by said base, brushes carried by said second lever and engaging said contacts, and pairs of contacts carried respectively by said first lever and said base, said pairs of contacts being adapted to selectively close in response to movement of said first lever and, when closed, to cause pivotal movement of said second lever in response to continued movement of said first lever to thereby move said brushes over said progressive contacts.

34. A switch mechanism comprising a pivoted lever, condition-responsive means operatively connected to said lever for controlling the position thereof, a double-throw switch means, a progressive switch means, and means whereby said lever independently and selectively actuates both of said switch means at any given position.

HAZOR J. SMITH. 

